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From: khalasa@piap.pl (Krzysztof =?utf-8?Q?Ha=C5=82asa?=)
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: lkml <linux-kernel@vger.kernel.org>
Date: Thu, 18 Sep 2014 15:12:02 +0200
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Subject: [PATCH] Fix unbalanced mutex in dma_pool_create().
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dma_pool_create() needs to unlock the mutex in error case.
The bug has been present starting with v3.16-rc1 (cc6b664a).

Signed-off-by: Krzysztof Hałasa <khc@piap.pl>
Cc: stable@vger.kernel.org

--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -174,11 +174,11 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 
 	mutex_lock(&pools_lock);
 	if (list_empty(&dev->dma_pools) &&
 	    device_create_file(dev, &dev_attr_pools)) {
 		kfree(retval);
-		return NULL;
+		retval = NULL;
 	} else
 		list_add(&retval->pools, &dev->dma_pools);
 	mutex_unlock(&pools_lock);
 
 	return retval;

-- 
Krzysztof Halasa

Research Institute for Automation and Measurements PIAP
Al. Jerozolimskie 202, 02-486 Warsaw, Poland